Maryland Code, Courts and Judicial Proceedings § 8-310

(a)(1) At each interval set in a jury plan for a county, its jury commissioner shall have names of qualified jurors selected in the number that the jury commissioner decides will satisfy the needs for jury service during the interval.

(2) Subject to § 8-421 of this title, a jury commissioner shall have enough names selected to allow parties to make peremptory challenges as allowed under this title or otherwise provided in the Maryland Rules.

(c)(1) Subject to paragraph (2) of this subsection, a jury commissioner shall allocate names from the qualified juror pool to grand and trial juries as the jury plan provides.

(2) Except as needed to complete service in a particular case or as otherwise provided in a jury plan, an individual may not be required, in any 3-year period, to serve or attend court for jury service more than once.